Biodiesel is a non-petroleum-based diesel fuel. Production of fatty acid alkyl esters for use as biodiesel comprises the transesterification of fatty acids of a feedstock into fatty acid alkyl esters. Natural fats and oils that make up the feedstocks for biodiesel production generally contain free fatty acids as either a naturally occurring component or as a result of an enzymatic decomposition process.
Generally, the transesterification reaction is carried out in the presence of an alcohol and a catalyst. Conventional methods of biodiesel production utilize either a batch reactor or a continuous process. These methods do not yield a conversion of fatty acids to fatty acid alkyl esters at a rate above 99%. The reaction times can also vary from several minutes to several hours. Batch process reactions are easy to control but are often cost ineffective due to ineffective mixing methods and long reaction times. Continuous transesterification processes can reduce the reaction times but have been unable to provide efficient mixing necessary to reduce the time and cost to produce biodiesel.
Accordingly, there is a need in the art for an apparatus and method of converting fatty acids to fatty acid alkyl esters that is cost effective and reduces reaction time. The apparatus and method can be easily retrofitted into an existing biodiesel production process. The apparatus and method can provide effective mixing such that the conversion rate of fatty acid into fatty acid alkyl esters is sufficiently high, and preferable above 90%.